/* Copyright (C) 1998, 2000, 2005 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include <errno.h> #define __need_NULL #include <stddef.h> #include <signal.h> #include <string.h> /* For the real memset prototype. */ /* Set the disposition for SIG. */ __sighandler_t sigset (int sig, __sighandler_t disp) { struct sigaction act, oact; sigset_t set; /* Check signal extents to protect __sigismember. */ if (disp == SIG_ERR || sig < 1 || sig >= NSIG) { __set_errno (EINVAL); return SIG_ERR; } #ifdef SIG_HOLD /* Handle SIG_HOLD first. */ if (disp == SIG_HOLD) { __sigemptyset (&set); __sigaddset (&set, sig); /* Add the signal set to the current signal mask. */ sigprocmask (SIG_BLOCK, &set, NULL); /* can't fail */ return SIG_HOLD; } #endif /* SIG_HOLD */ memset(&act, 0, sizeof(act)); act.sa_handler = disp; /* In Linux (as of 2.6.25), fails only if sig is SIGKILL or SIGSTOP */ if (sigaction (sig, &act, &oact) < 0) return SIG_ERR; /* Create an empty signal set. Add the specified signal. */ __sigemptyset (&set); __sigaddset (&set, sig); /* Remove the signal set from the current signal mask. */ sigprocmask (SIG_UNBLOCK, &set, NULL); /* can't fail */ return oact.sa_handler; }